Casing cutter



Feb. 18, 1930. 1, A, KAMMERDINER 1,747,5123

GASING CUTTER Filed' Dec. 21, 1925 Patented Feb. 18, 1930 UNITED STATES :rAMEs ALLEN .'KAMMEED'TNEE, 0E. Los ANGELES, oAL1EoENIA,Ass'IeNoE .0E TEN ONE-HUNDREDTHs To o. P. YowELL, TEN @NE-HUNDREDTHS To s. E. noErN'so'N, TEN oNE-H'UNDEEDTHS To z. A. DYEP., AND TEN oNEnUNnEEDTHs To c. T. ALLEN oAsING CUTTER Application led December 21, 1925.

L This invention relates to a device for severing tubular members. It is especially useful in cutting casings in oil well holes and like places. For various reasons, it is often'necessary or advisable to cut casing within the hole and at a considerable depth. The presentV invention has for its primary object the provision of a toolwhich may be inserted in the hole about the work or member to be cut in the mannerr of an overshot fishing tool. That is, the tool encircles or embraces the work or casingto be cut and slides along on it' while being lowered to the 4desired point. The tool is then caused to puncture and sever the member by Vmoving the' tool upwardly. Another object of this invention is to provide a tool of the character described which produces aseveranc'e by progressively perforating the w-ork along the line of severance so as to finally produce a peripheral cut. The ultimate object of this invention is to produce a cutter which requires an operating force of relatively small magnitude and may be operated by pulling upwardly.

These objects together with other objects and corresponding accomplishments are obtained by means of the embodiment of my invention illustrated in the accompanying drawing, in which: Y Y

Fig. 1 is an axial section through a cutting tool showing it disposed abouta casing and in position for operation; Fig. 2 is a section as seen on the line 2-2 of Fig. 1; Fig. 3 is an axial section on an enlarged scale showing a fragment of the tool and the casing with a knife in position about to perforate the casing; and Fig. 4 is a View similar to Fig. 3 'showing a -knifeafter it hasperformed its cutting function. 'Y j Referring more particularly to the drawings, A andB indicate joints of casing joined by. a coupling C. This is the usual structure of the casingkstring. It Vvwill be assumed that the casing is to be cut below the coupling.

i A tubular body or shell 5 has a bore extending therethrough and indicated by 6 so it may be passed over the casing and couplings. vThe bore is constricted at the top as indicatedby 7. It is counterbored and internally threaded as indicated by 8 to receive the end of 4a pipe Serial No. 76,664.

9 forming the string for operating the tool. An enlargement 10 is provided at an intermediate portion of the bore to receive an abutment ring later described. The bore is still further enlarged as indicated by 11 for receiving knife carrier rings. The lower end of the bore is threaded as indicated by 12 to receive a shoe 13.

Slidably mounted within the portion 10 of the bore is a ring 14 having spring fingers These lingers are arranged to press inwardly against the string of casing and toengage the underside of adjacent ,coupling C which forms', in eect, a shoulder, if the ring is moved upwardly. Extendingthrough registering openings in the bodyA and ring is a shear pin 16. This pin yieldably retains ring 14 in longitudinal position and constitutes a frangible member, that is when suiicient force is exerted upon ring 14 tending Ato move it downwardly, the p in16 will be sheared as shown in Fig. 3. The ring has a shoe as indicated by 17 at its lower end which is preferably made of soft metal.

Disposed within the portion 11 of the bore of the ,body is a plurality of knife carriers or cages 18 to 22. These comprise rings which arel similar in construction and dimensions and are held in position by the shoe 13. The internal diameters of the rings vcorrespond to the external diameter of the abutment ring 14 so that it may be slidably .moved thereinto. Referring to ring 18, it has a 'number Yof longitudinally extending slots or recesses 23 in which are disposedv knife blades 24.V The blades have sharp ends for engaging and perforating the casing. They are Vplvoted on pins 25 in the carrier so that they be turned about their pivots vmoving inwardly.

15 secured thereto and extending upwardly. n

The pins or axes 25, extend peripherally mounted on their pivot pins and would drop ,100

downwardly, unless held in their upper potudinally.

sition. The bindingwire serves for this purpose and is a frangible retention member, it being easily sheared when pressure is eX- erted thereon. In the present structure there are' ive carrier ringsshown, each havinga setv .of knives spaced about its periphery,,therei- -rier ringsserving to space thekniveslongi- In assemblingr the carrierswrV cages inthe'shell A5,?the knives should be disposedp'eripherally 'in staggeredl relation.

This maybe insured-by v-having dowel pins 29 engaging corresponding recesses in the ends be moved upwardly while lthe abutment ring l' la remains 'stationary rIhe set of knives on carrier Irin g 18 yengage ,the lower end' of vrthe abutment ring, as shown in ig.- 3, :andshear ivire`27, and are turned inwardly against the casing so las .to puncture Ithe latter. lContinnedv movement `ofthe tool Vupwardly causes the knives Yto be withdrawn ,and to be disposed in the final inoperative position shown in Fig. 4. VNext theset of knives in earrier ring 19 engagethe labutment ring' and the binding wireis 'shea-red, the knives' turned inwardly and puncturing Ithe casing at' points A'intermediate the other 'perforationa producing another set of .perforations "The knives in- ...carrier ring 20 Ynext ac'tland then vtlrse'in lrings-21 .and 22. ",lhe perforatins produe'ed all'offthe knives aetingseverthe vcg'j'n'i'pletely and lthelatterl may then be raised with the tdol. `Itzwill be noted that v.the cutting is .accomplished perforating .the 4pipe at intervals so that the magnitude of force 'required isi'comparatively small.

' What I `claim is:

y`l. A'tol ofthe character described comprising a shellV for slidably embracing the 'workto bews'evered, an abutment member disposed `'withinsaidV shell -so as to be yieldahly retained in longitudinal position therein, said f abutment Vmember havingmeans to vengage a shoulder on the work when moved inone i' direction, a plurality of spaced annular knife cages mounted in said shell, each of said qcages having l. longitudinally extending recesses, knives pivdtally mounted within the recesses 0f Seid Cases@ periplirally @needing axs,

the'knives in each Cage being staggered withI respeet .to the -kn-ivesin the v otl'rer cages, said knivesbeing arranged tbr SWlmgin'a vcontinuous movement from an initial inoperative "2. A tooll'ofith'e characterdeseribed com if prising a shell for slidably embracing the work ftoibe severed, an abutment memberdis'- posed within said 'shell solas .to lbe .yieldably retainedin longitudinal. position :therein,.said

abutment member having means to engage a shoulder on thevwork when moved in one direction,a plurality l olii annular knife cages mounted in said shell, each of said cages haviiis -leiieitudnally .extending recesses., knives pivotally mounted .within the recesses sof cages' .oil iiriplierally .extending 'a2-ies; the.

knives iii @zich @ase heilig .Staeseiefivitli ref Select tothe .knives .ii the .ailier 'sages said tinuous .movement'from `initial linopera,- tive position inwardly so as .to `penetrate Llthe verk andlili'eii .be Withdrawn/1,111,120 .mors/retire position again., and yieliiable izieiiiionmeaii to hold. said knive'sfirivinitial inoperative `po-y sitiQmSaid'abutment member beingarranged to .be engaged by rsaid 4knives tobSWing ,the latter. n i 31A ,tool 'of thecharaeter Tdescribed .coins prisme@ Shell for Slideblv .embracing .the work to be severed, anabutment ring lidably .disposed viiliiii .Seid shell, a 1b bei-fiamminga@@ingame ma sp i @Mehrfam @milled :Q11 .Seid .ring .tending t0 .displace .the latter may break` said ble member and release said ring, .a'lgnijie y gin .mounted in .Said r.Sflilf'l-l hj ving longitudinally .eXteIiliIig' slots,v knives piyiflltelly simili-led Wi'iliiii lli@ '5.1.0155 .of .said ses@ i011; rerirherally ble retention member .encircling Said seemed knives .1n initial inoperative pob holding said sitionf I 4. A tool of the iCharacter:described tcomprising a shell for slidably .embracing the WOilii@ be Severed., an. abutment -ririgslfl-y ably disposed Within Seid -slielh raiigible :member Securing Seid 'iiiig'iiiflilgiiuliiifll` position in said shell, fingers .on Said ring adapted t0. .iisasiliifler 'e Should... ...nili work whereby force exerted Von :said Vtending to displace the latter may ybreak said ineligible member @iid release seid fiiili e 'l in pliirfl'lity f .annular ,knife cagesiiieunt Saiil Shell, each O f Seid Qagif'liaviig lensi- .iiidiiially @Kissing slsie'zliliiivei .Pinelli ring.

mounted Within the slots of said cages on peripherally extending aXes, the knives in each cage being staggered with respect to the knives in the other cages and arranged to be swung in a continuous movement from an initial inoperative position inwardly so as to penetrate the work and then be withdrawn into inoperative position again, said abutment ring being arranged to be engaged by said knives to swing'the latter.

5. A tool of the character described comprising a shell for slidably embracingthe work to be severed, an abutment ring slidably disposed within said shell, a rangible member securing said ring in longitudinal position in said shell, fingers on said ring adapted to engage under a shoulder on the work, whereby force exerted on said ring tending to displace the latter may break said rangible member and release said ring, a plurality of annular knife cages mounted in said shell, each of said cages having longitudinally extending slots, knives pivotally mounted within slots of said cages on peripherally extending axes, the knives in each cage being staggered with respect to the knives in the other cages, said knives being arranged to be swung in a continuous movement from an initial inoperative position inwardly so as to penetrate the work and then be withdrawn into inoperative position again, said abutment ring being arranged to be engaged by said knives in their initial inoperative position and to swing the latter, and a frangible retention means Jfor each cage encircling the latter and engaging the knives therein to hold the latter in their initial inoperative position.

6. A tool of the character described comprising a body for slidably embracing the work to be severed, an abutment member disposed within said body so as to be yieldably retained in longitudinal position therein, said abutment member having means to engage a shoulder on the work to prevent movement in one direction, sets of knives pivotally secured to said body on peripherally extending ing axes, said sets of knives being disposed at different levels, said knives being mounted to be swung inwardly in a continuous movement so as to penetrate the work and be withdrawn to final inoperative position, said abutment member being arranged to be engaged by said sets of knives in seriatim and to swing the latter, and yieldable retention means to hold said knives in initial inoperative position.

In witness that I claim the foregoing I have hereunto subscribed my name this 12th day of December, 1925.

JAMES ALLEN KAMMERDINER. 

